/*
 * Copyright 2009-2009 Tanesha Project. All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without modification, 
 * are permitted provided that the following conditions are met:
 * 
 *    1. Redistributions of source code must retain the above copyright notice, 
 *    	 this list of conditions and the following disclaimer.
 *    2. Redistributions in binary form must reproduce the above copyright notice,
 *    	 this list of conditions and the following disclaimer in the documentation 
 *    	 and/or other materials provided with the distribution.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE FREEBSD PROJECT ``AS IS'' AND ANY EXPRESS OR 
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT 
 * SHALL THE FREEBSD PROJECT OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, 
 * OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF 
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE 
 * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 *  OF THE POSSIBILITY OF SUCH DAMAGE.
 * 
 * The views and conclusions contained in the software and documentation are those 
 * of the authors and should not be interpreted as representing official policies, 
 * either expressed or implied, of the Tanesha Project.
 */
package com.google.api.chart;

import java.util.ArrayList;
import java.util.List;

import com.google.api.chart.encoding.JoinHelper;

public final class LinearGradientFillMaker implements FillMaker {

	public static LinearGradientFillMaker fill() {
		return new LinearGradientFillMaker();
	}

	private String type = "bg";
	private double angle = 0.0;
	private List<String> offsets = new ArrayList<String>();
	
	private LinearGradientFillMaker() {
	}

	@Override
	public String toString() {
		return type + ",lg," + JoinHelper.doubleFormat(angle) + "," + JoinHelper.join(JoinHelper.array(offsets, String.class), ",");
	}
	
	public LinearGradientFillMaker background() {
		this.type = "bg";
		return this;
	}

	public LinearGradientFillMaker chart() {
		this.type = "c";
		return this;
	}
	
	public LinearGradientFillMaker angle(double angle) {
		if (angle < 0.0 || angle > 90.0)
			throw new IllegalArgumentException("angle must be in [0, 90]");
		this.angle = angle;
		return this;
	}
 
	public LinearGradientFillMaker color(double offset, ColorMaker color) {
		if (offset < 0.0 || offset > 1.0)
			throw new IllegalArgumentException("offset must be in [0, 1] (0 = right-most, 1 = left-most)");
		offsets.add(color.toString() + "," + JoinHelper.doubleFormat(offset));
		return this;
	}

	public boolean isBackground() {
		return "bg".equals(type);
	}
}
